In usual equipment for manufacturing the semiconductor wafers, the carrier robot is provided, in a clean room, for taking out and holding each semiconductor wafer from a base station and then carrying and transferring the semiconductor wafer to a target station for a next production step. FIG. 8 schematically shows general construction of such a semiconductor-wafer carrier robot.
As shown in FIG. 8, the semiconductor-wafer carrier robot 100 includes a horizontal base 101, a vertical post 102 supported by the horizontal base 101, such that this post 102 can be moved in the horizontal direction along the horizontal base 101, a robot main body 103 supported by the vertical post 102, such that this robot main body 103 can be moved in the vertical direction along the vertical post 102, and a wiring/piping bundle 104 provided, along the horizontal base 101 up to the vertical post 102, for actuating and controlling the robot main body 103 and related mechanisms thereof.
More specifically, the robot main body 103 includes a robot base 103a supported by the vertical post 102, such that this robot base 103a can be moved in the vertical direction along the vertical post 102, a plurality of robot arms (e.g., in this case, two robot arms) 103b, 103c (wherein a proximal end of the arm 103b is connected via an axis with a distal end of the robot base 103a, while a distal end of the arm 103b is connected via another axis with a proximal end of the arm 103c), and a robot hand 103d connected via still another axis with a distal end of the robot arm 103c. In this case, each of the robot arms 103b, 103c and robot hand 103d can be rotated in the horizontal direction about each corresponding axis.
With this configuration, in which the vertical post 102 is supported by the horizontal base 101, such that this post 102 can be moved in the horizontal direction along the horizontal base 101, in which the robot base 103a is supported by the vertical post 102 such that this robot base 103a can be moved in the vertical direction along the vertical post 102, and in which the robot arms 103b, 103c and robot hand 103d are connected with one another such that each of the arms and hand 103b, 103c, 103d can be rotated in the horizontal direction relative to the robot base 103a, each semiconductor wafer (not shown) held by the distal robot hand 103d can be carried and transferred to the target position, while being moved three-dimensionally.
The wiring/piping bundle 104 for actuating and controlling the robot main body 103 and related mechanisms thereof includes power-supply cables, compressed-air pipes and/or vacuum pipes, control signal lines respectively connected with sensors, and the like. In particular, such power-supply cables are respectively connected with drive mechanisms (not shown), each adapted for driving a motor or the like means provided for horizontally moving the vertical post 102, vertically moving the robot base 103a, or horizontally rotating each of the robot arms 103b, 103c and robot hand 103d. 
This wiring/piping bundle 104 is inserted through a base-side protective pipe 105 formed of a rigid pipe and horizontally fixed onto the horizontal base 101, and further introduced into the vertical post 102 via a side thereof through a flexible cable bear (registered trademark) 106. In this case, each cable, pipe or line included in the bundle 104 is introduced into the vertical post 102, and then distributed and connected to each corresponding drive mechanism. In FIG. 8, for convenience, the cable bear 106 is illustrated by imaginary lines. For instance, such a cable bear 106 is reported in JP2003-37153A.
In the case of the robot 100 constructed as shown in FIG. 8, during the horizontal movement of the vertical post 102 along the horizontal base 101, the wiring/piping bundle 104 will be moved following the movement of the vertical post 102 over the horizontal base 101, while being inserted and supported through the cable bear 106 and turned around by 180°.
In such a sharply curved portion, rather great stress is exerted on the wiring/piping bundle 104, leading to generation of unwanted dust also called particles due to wear and tear of the wiring/piping bundle 104 and/or friction between the bundle 104 and the cable bear 106. In order to avoid the generation of such dust or particles, it is necessary to considerably enlarge the radius of curvature of the curved portion. Thus, when the post 102 is located in a waiting position (as depicted by a solid line in FIG. 8), a projection amount D in the horizontal direction of the curved portion is rather increased, making it difficult to achieve a more compact form of this robot.
For instance, in the carrier robot shown in FIG. 8, the maximum movable range of the vertical post 102 between the waiting position thereof depicted by the solid line and a maximum transfer position thereof depicted by a two-dot chain line is expressed by a distance L. In this case, as described above, the wiring/piping bundle 104 is moved, while being turned around by 180°. Thus, as illustrated in the drawing, the movable range Lm of the curved portion (i.e., a horizontal distance between a proximal point of the curved portion when the post 102 is in the waiting position thereof and the proximal point of the curved portion when the post 102 is in the maximum transfer position thereof) is approximately equal to ½ L (i.e., Lm=½ L). Accordingly, the length of the curved portion including such a wide movable range Lm thereof that should be supported by the cable bear 106 has to be considerably elongated. Therefore, such configuration of the carrier robot, as illustrated and described above, may tend to cause generation of so much dust or the like.
Further, since the wiring/piping bundle 104 is sharply curved at the curved portion thereof, parts of the cable bear 106 itself are also likely to be in frictional contact relative to one another. This may also tend to generate the dust or the like. Especially, in the equipment for manufacturing the semiconductors, the generation of such dust may have serious impact on the quality of each product. Therefore, in some measure, an additional means for covering the cable bear 106, such as by using a separate cover, is provided, thus further enlarging the size of such equipment.